I. Field
The following description relates generally to wireless communications, and more particularly to employing power save delivery mechanisms with direct link set-up connections.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems can be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems can include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP2, 3GPP long-term evolution (LTE), etc.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple mobile devices. Each mobile device can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Further, communications between mobile devices and base stations can be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or base stations with other base stations) in peer-to-peer wireless network configurations.
Wireless communication systems can employ one or more base stations or access points that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream can be a stream of data that can be of independent reception interest to an access terminal. An access terminal within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, an access terminal can transmit data to the base station or another access terminal.
In addition, wireless communication system can include network such as wireless wide area networks (WWANs) that provide communication coverage for large geographic areas (e.g., cities), wireless local area networks (WLANs) that provide communication coverage for medium-size geographic areas (e.g., buildings and campuses), and wireless personal area networks (WPANs) that provide communication coverage for small geographic areas (e.g., homes). A wireless network typically includes one or more access points (or base stations) that support communication for one or more user terminals (or wireless devices).
IEEE 802.11 is a family of standards developed by The Institute of Electrical and Electronics Engineers (IEEE) for WLANs. These standards specify an over-the-air interface between an access point and a user terminal or between two user terminals. IEEE Std 802.11, 1999 Edition (or simply, “802.11”), which is entitled “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications,” supports data rates of 1 and 2 mega bits/second (Mbps) in the 2.4 giga Hertz (GHz) frequency band using either frequency hopping spread spectrum (FHSS) or direct sequence spread spectrum (DSSS). IEEE Std 802.11a-1999 (or simply, “802.11a”) is a supplement to 802.11, uses orthogonal frequency division multiplexing (OFDM) instead of FHSS or DSSS, and supports data rates of up to 54 Mbps in the 5 GHz frequency band. IEEE Std 802.11b-1999 (or simply, “802.11b”) is another supplement to 802.11 and uses DSSS to support data rates of up to 11 Mbps. IEEE Std 802.11g-2003 (or simply, “802.11g”) is yet another supplement to 802.11, uses DSSS and OFDM, and supports data rates of up to 54 Mbps in the 2.4 GHz band. These various standards are well known in the art and publicly available.
The lowest data rate supported by 802.11, 802.11a, 802.11b and 802.11g is 1 Mbps. For 802.11b and 802.11g (or simply, “802.11b/g”), a specific DSSS scheme and a specific modulation scheme are used to send a transmission at the lowest data rate of 1 Mbps. The DSSS and modulation schemes for 1 Mbps require a certain minimum signal-to-noise-and-interference ratio (SNR) for reliable reception of the transmission. The range of the transmission is then determined by the geographic area within which a receiving station can achieve the required SNR or better.